Specification: Material: PCB board + LED lamp + Battery + Double-sided tape + EVA foam LED Quantity: 6 LED for one coaster Power: 2 x CR1220 batteries(included and installed) Dimension of LED Coasters: 6 x 0.5cm Package Includes: 20 x LED Coaster White led light coasters: Color: White 3 modes: rapid flash, slow flash and steady mode Blue led light coasters: Color: Blue 3 modes: rapid flash, slow flash and steady mode Colorful led light coasters: 7 colors: white, red, blue, green, yellow, purple, ice blue 8 modes: each single color steadily bright and multi-color flash in turn Easy to Use: Take out the insulation insert Tear off the double-sided tape Stick up to the bottle bottom Press the bottom power to use Note: The battery panel were embedded in the LED coasters panel, do not wash directly, clean with wet wet duster cloth.